Geodynamique et Structure

Bagneux, France

Geodynamique et Structure

Bagneux, France
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Agency: European Commission | Branch: FP7 | Program: CP-CSA-Infra | Phase: INFRA-2008-1.1.2 | Award Amount: 10.72M | Year: 2009

European seismic engineering research suffers from extreme fragmentation of research infrastructures (RI) between countries and limited access to them by the S/T community of earthquake engineering, especially that of Europes most seismic regions. A 23-strong Consortium of the key actors in Europes seismic engineering research (including 3 industrial partners) addresses these problems in a sustainable way via a 4-year programme of activities at an annual cost to the Commission less than 1.35% of the total present value (190m) of the RIs material resources. The scope covers all aspects of seismic engineering testing, from eight Reaction Wall Pseudodynamic (PsD) facilities and ten Shake Table labs, to EUs unique Tester of Bearings or Isolators, its two major Centrifuges and an instrumented Site for wave propagation studies. Transnational Access is offered to a portfolio of world class RIs: EUs largest PsD facility, four diverse Shake Tables and the two Centrifuges. Networking sets up a public distributed database of past, present and future test results, installs distributed testing capabilities at all PsD labs, fostering development of up-and-coming ones at Europes most seismic regions, drafts and applies protocols for qualification of RIs and engages the entire European community of earthquake engineering via the best possible instances: the European Association of Earthquake Engineering, EUs seismic code makers and their national groups, the European Construction Industry, as well as all relevant S/T associations or networks. Joint research engages all labs, exploring and prototyping novel actuators (combination of electro-dynamic and hydraulic ones) for better control of fast tests or special applications, new sensing and instrumentation systems, data assimilation in equipment-specimen models for better test control and optimisation of testing campaigns, as well as experimental studies of soil-structure interaction at all types of testing facilities.

Pecker A.,Geodynamique et Structure | Pecker A.,ParisTech National School of Bridges and Roads | Paolucci R.,Polytechnic of Milan | Chatzigogos C.,Geodynamique et Structure | And 2 more authors.
Bulletin of Earthquake Engineering | Year: 2014

In this paper we provide an overview of recent research work that contributes to clarify the effects of non-linear dynamic interaction on the seismic response of soil-foundation-superstructure systems. Such work includes experimental results of seismically loaded structures on shallow foundations, theoretical advancements based on improved macro-element modeling of the soil-foundation system, examples of seismic design of bridge piers considering non-linear soil-foundation interaction effects, and numerical results of incremental non-linear dynamic analyses. The objective of this paper is to support the concept of a controlled share of ductility demand between the superstructure and the foundation as a key ingredient for a rational and integrated approach to seismic design of foundations and structures. © 2013 Springer Science+Business Media Dordrecht.

Figini R.,ENEL S.p.A | Paolucci R.,Polytechnic of Milan | Chatzigogos C.,Geodynamique et Structure
Earthquake Engineering and Structural Dynamics | Year: 2012

In this paper, different formulations of a macro-element model for non-linear dynamic soil-structure interaction analyses of structures lying on shallow foundations are first reviewed, and secondly, a novel formulation is introduced, which combines some of the characteristics of previous approaches with several additional features. This macro-element allows one to model soil-footing geometric (uplift) and material (soil plasticity) non-linearities that are coupled through a stiffness degradation model. Footing uplift is introduced by a simple non-linear elastic model based on the concept of effective foundation width, whereas soil plasticity is treated by means of a bounding surface approach in which a vertical load mapping rule is implemented. This mapping is particularly suited for the seismic loading case for which the proposed model has been conceived. The new macro-element is subsequently validated using cyclic and dynamic large-scale laboratory tests of shallow foundations on dense sand, namely: the TRISEE cyclic tests, the Public Works Research Institute and CAMUS IV shaking table tests. Based on this comprehensive validation process against a set of independent experimental results, a unique set of macro-element parameters for shallow foundations on dense sand is proposed, which can be used to perform predictive analyses by means of the present model. © 2011 John Wiley & Sons, Ltd.

Lambert S.,Geodynamique et Structure | Chatzigogos C.,Geodynamique et Structure | Chatzigogos C.,Aristotle University of Thessaloniki | Godoy A.,Geodynamique et Structure
COMPDYN 2015 - 5th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering | Year: 2015

Modeling of soil-structure interaction for shallow foundations entails three sources of nonlinearities: foundation uplifting, sliding along the soil-footing interface and irreversible displacement due to soil plasticity. Foundation macroelements allow reducing computational efforts in the resolution of seismic response including nonlinear soil-structure interaction. This is achieved by replacing the soil domain and the foundation by a 2-noded element with a sophisticated nonlinear constitutive law reproducing the aforementioned non-linearities. Definition of uplift and soil plasticity models and of the coupling between the two require a set of parameters that depend on the soil characteristics and the foundation geometry. For practical applications, calibration of these parameters is required. In this paper, calibration tables have been produced for the parameters describing the foundation uplift behavior. In the case of a rectangular foundation (that has been calibrated for the first time), two extra parameters are introduced with respect to the strip and circular footing: the footing aspect ratio and the direction angle of the resultant overturning moment. In addition, a standardized methodology has been proposed to calibrate the parameters describing soil plastic behavior. The macroelement validation procedure has been carried out in the case of a bridge pier founded on a strip footing. The discrepancy between macroelement calculations and detailed finite element modeling has been evaluated for twenty earthquake records. Prediction of the superstructure maximum displacements (mean error < 10 %, standardized deviation < 20%) and efforts (mean error < 20 %, standardized deviation < 10%) is validated. Macroelement limitations concern the evaluation of foundation residual displacements, suggesting that further development should be focused on the improvement of plasticity model for soil irreversible behavior.

Sullivan T.J.,University of Pavia | Salawdeh S.,MEEES Graduate | Pecker A.,Geodynamique et Structure | Corigliano M.,EUCENTRE | Calvi G.M.,EUCENTRE
Soil-Foundation-Structure Interaction - Selected Papers from the International Workshop on Soil-Foundation-Structure Interaction, SFSI 09 | Year: 2010

Modern earthquake engineering appears to be embracing the concepts of performance-based seismic design. This is becoming possible because the past decade has seen the development of a range of tools for performance-based seismic design, including the direct displacement-based design method. Much of the developments made to date, however, have focused on the performance-based design of structures without consideration of soil-foundation structure interaction. In this work a number of SFSI considerations are made for performance-based design of reinforced concrete wall structures on shallow foundations. In particular, possible performance criteria for foundation systems are discussed, existing methods of accounting for SFSI in seismic design are reviewed and a new Direct DBD procedure to account for SFSI in RC wall structures is proposed. The design procedure is applied to a number of case study structures to highlight the impact of SFSI on design requirements, and trends are compared with force-based design solutions. © 2010 Taylor & Francis Group.

Joly E.,VINCI Construction Grands Projets | Moine P.,VINCI Construction Grands Projets | Pecker A.,Geodynamique et Structure
Multi-Span Large Bridges - Proceedings of the International Conference on Multi-Span Large Bridges, 2015 | Year: 2015

The Greek bridge at the edge of the Gulf of Corinth is a vital part of the trans- European road network, it links the Peloponnesus to the mainland in a high seismicity area; it has been built from 1998 to 2004. Its innovative design, from the isolated shallow foundations to the 2252m continuous deck, is still to date an inspiration for projects around the world. © 2015, Taylor & Francis Group, London.

Pecker A.,Geodynamique et Structure | Chatzigogos C.T.,Geodynamique et Structure
Geotechnical, Geological and Earthquake Engineering | Year: 2010

The paper presents results of incremental dynamic analyses (IDA) of a simple structural system with consideration of non linear soil structure interaction. The analyses are facilitated using a non linear dynamic macroelement for the soil-foundation system. Three base conditions are examined, namely fixed base, linear foundation and non-linear foundation including uplift and soil plasticity. IDA curves are produced for a variety of intensity and damage parameters describing both the maximum and the residual response of the system. The results highlight the beneficial role of foundation non linearities in decreasing the ductility demand in the superstructure but point out the need to carefully assess the variability of the response when non linearity is allowed at the foundation design. © Springer Science+Business Media B.V. 2010.

Pecker A.,Geodynamique et Structure | Pecker A.,ParisTech National School of Bridges and Roads
Geotechnical, Geological and Earthquake Engineering | Year: 2015

The topic of this paper is to illustrate on a real project one aspect of soil structure interaction for a piled foundation. Kinematic interaction is well recognized as being the cause of the development of significant internal forces in the piles under seismic loading. Another aspect of kinematic interaction which is often overlooked is the modification of the effective foundation input motion. As shown in the paper such an effect may however be of primary importance. © The Author(s) 2015.

Scotta R.,University of Padua | Giorgi P.,University of Padua | Tesser L.,Geodynamique et Structure | Talledo D.A.,IUAV University of Venice
11th World Congress on Computational Mechanics, WCCM 2014, 5th European Conference on Computational Mechanics, ECCM 2014 and 6th European Conference on Computational Fluid Dynamics, ECFD 2014 | Year: 2014

A numerical model for the nonlinear analysis of R/C shear walls under cyclic seismic loadings has been proposed by some of the authors. It is here validated by comparison with three experimental tests taken from literature on R/C complex shear walls. The finite element numerical models consider both in-plane loaded membrane elements and out-of-plane loaded plate elements. Reinforcing bars are modelled as multiple smeared steel layers for which uniaxial stress-strain relation with isotropic hardening according to the Menegotto-Pinto constitutive model was adopted. The concrete material description is based on continuum damage mechanics and uses two independent scalar damage parameters to describe inelastic response of the material. At this stage of the research the bond-slip between concrete and rebars is not taken into account. Two of the experimental tests considered for the validation were conducted at the NEES MUST-SIM Facility - University of Illinois and concern both planar and coupled complex wall systems. The third experimental program was conducted at ELSA Laboratory (JRC Ispra) within the framework of TMR-ICONS TOPIC 5 program on an U-shaped wall cyclically loaded along two orthogonal directions. All tests were carried out in quasi-static conditions. The good fitting of the numerical results with the experimental ones demonstrates the robustness and efficacy of the proposed numerical model in reproducing the cyclic behaviour of R/C members on both two-dimensional and three-dimensional problems.

Fernandez C.,PST Innovation | Bourgouin L.,PST Innovation | Riegert F.,6 rue Raoul Nordling | Pecker A.,Geodynamique et Structure
Proceedings of the Biennial International Pipeline Conference, IPC | Year: 2012

At CRIGEN, the GDF SUEZ research center for gas and new energies, a project on risk management on gas infrastructures (MARTHO project) is aimed, among other goals, at protecting the pipelines against external aggressions such as vibrations. Over the past few years, extensive construction of wind turbines has taken place all around the world in areas where many steel pipelines are already buried. The possible fall of these heavy machines may induce damageable vibrations to the pipeline. The common threshold used by the industry, established by the American Gas Association, is stated1 at PPV ≤ 50 mm.s-1. A more accurate and less conservative model of vibration propagation has been developed and validated by extensive field measurements coupled with a nonlinear 2D-finite element model for the soil. An experimental soil characterization through MASW tests coupled with vibration measurements was performed in a representative soil. As a result, safety distances between wind turbines and pipelines were considerably shortened compared to the previous model. The updated model is now part of the RAMCES software which has been developed for more than a decade at CRIGEN and is widely used in France by transmission operators. Copyright © 2012 by ASME.

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